Cutibacterium acnes (C acnes) colonisation can have a significant impact on patients undergoing both arthroscopic and open shoulder surgery with regards to post-operative infection. Its resistance to standard pre-operative skin preparations and prophylactic antibiotics has led to a need for a more targeted therapy. Topical benzoyl peroxide (BPO) has been used by dermatologists in the treatment for acnes due to its bactericidal and penetrative effects through the dermal layer. The aim of this systematic review is to review the effectiveness of topical BPO pre-operatively in shoulder surgery in reducing C acnes colonisation and post-operative infection.
A review of the online databases Medline and Embase was conducted on 15 December 2021 according to PRISMA guidelines. The review was registered prospectively in the PROSPERO database. Clinical studies reporting superficial and deep sample microbiology and post-operative complications were included. The studies were appraised using the revised Cochrane Risk of Bias (ROB 2) tool for randomised studies and the Methodological Index for Non-Randomised Studies (MINORS) tool.
The search strategy identified ten studies for inclusion (six randomised control trials, two prospective cohort studies and two case series), including a total of 482 patients. Seven studies were comparable, testing BPO against alternative standard skin preparations. Of the ten studies, seven showed a decrease in the load of C acnes on the skin and/or deep tissues of which six demonstrated statistical significance. Men were shown to have a statistically significant increase in the colonisation rate of C acnes, Scheer et al 2021 demonstrated 4500 CFU/ml in males and 900 CFU/ml in females. In studies where the number of BPO applications was higher, BPO appeared more effective. Dizay et al demonstrated C acnes elimination in 78.9% with more than one application compared to 66.7% if only applied once. Three studies looked at the effectiveness of BPO during the operative timeline with one demonstrating its statistically significant effectiveness at reducing colonisation two hours into the operation (p = 0.048).
BPO is effective as a topical treatment at reducing C acnes colonisation prior to shoulder surgery. However, the relationship between duration of treatment, frequency of application and gender require further research.
Level of evidence: IV; Systematic review.